Electrical connectors for interconnecting a circuit board backplane to a daughterboard generally comprise two mating connector halves each having multiple rows and columns of conductive elements or contacts. It is known to provide each column of contacts as a separate module that includes a vertical array of contacts having an overmolded carrier. Multiple modules are installed in a connector housing to form a complete connector. See, for example, U.S. Pat. No. 5,066,236. Generally, all of the modules in such a connector are substantially identical. However, there are times when it would be desirable to have different types of modules in a connector in order to accommodate different electrical characteristics of signals through the connector. A problem results in that additional tooling and handling is required for the different types of modules, thereby increasing manufacturing costs.
The backplane to daughterboard connectors have a high contact density and are required to operate at relatively high electrical speeds. Due to continuing trends toward miniaturization and improved electrical performance by the electronics industry, requirements for greater contact density and higher electrical speeds are constantly being promulgated. These requirements lead to design conflicts, especially when electrical speeds are in the range of approximately 500 megahertz and above, due to the fact that increasing the contact density places the contacts in closer proximity to each other, thereby leading to crosstalk between neighboring contacts in different signal pairs.